When this whirlwind season is over, Xander Bogaerts said he plans to return to Aruba, go to the beach, sit on the sand and reflect on how he went from part of the Red Sox’ future to part of their World Series team.

That makes sense because Bogaerts has made pressure-packed postseason at-bats look like a day at the beach. It’s Shane Victorino who comes to the plate to Bob Marley’s “Three Little Birds” with those famous lyrics, “Don’t worry about a thing . . . ” But it’s the barely-drinking age Bogaerts who is the personification of those lyrics in his first postseason.

Just like the next great Red Sox team has arrived ahead of schedule, so has the Red Sox Next Big Thing. There is an aphorism in sports that says, “Rookies don’t know what rookies don’t know.” In Bogaerts case, he doesn’t know that he shouldn’t be this calm, this comfortable, and this good on such a big stage so early in his career.

When the Sox open the World Series on Wednesday at Fenway Park against the St. Louis Cardinals, Bogaerts will be at third base. At the tender age of 21 years, 22 days he will supplant Babe Ruth as the youngest Red Sox to start a World Series game. The Babe was 21 years and 246 days when he pitched in the 1916 World Series.

Hype springs eternal when it comes to prospects. Potential is the most intoxicating elixir in all of sports and fans and front offices can both become drunk on it. But rarely do the talents of the young match up with the expectations we heap on them right away.

Just ask Tyler Seguin or the Patriots’ rookie receivers. But Bogaerts has exceeded expectations, all while adjusting to a position — third base — that is about as natural to him as the concept of a snow day.

After the left side of the Sox infield scuffled in the first four games of the American League Championship Series, manager John Farrell replaced Will Middlebrooks with Bogaerts for Game 5. The kid responded by going 2 for 4 with three walks and three runs scored in the final two games of the series.

It was the Bogey Man’s six-pitch walk in the seventh inning of Game 6 that chased Tigers ace Max Scherzer and paved the way for Victorino to hit a grand slam off Jose Veras, one of the incendiary devices in the Detroit bullpen.

Earlier in the game, Bogaerts scored Boston’s first run after rocketing a fifth-inning double off the soon-to-be Cy Young winner.

A kid who doesn’t seem surprised by anything admits he didn’t foresee a season that started by playing for the Netherlands in the World Baseball Classic in March ending by playing in the World Series in October.

“No, no, definitely not,” said Bogaerts, who in August became the youngest Sox player to make his major league debut since Dwight Evans in 1972. “It’s been a whirlwind season. It started from spring training to the WBC to Double A, Triple A, here, big leagues, postseason, World Series. I’m definitely enjoying every step of it.”

It’s hard to tell what is most impressive about Bogaerts — his uncommon plate discipline, his unflappability or his easy-going humility. All are signs of a player behaving beyond his years.

The plate discipline has been exemplary, even on a team that has made seeing pitches its dogma. Bogaerts has walked five times in 11 plate appearances, including twice coming off the bench in the clinching game of the American League Division Series against the Tampa Bay Rays.

“It’s been amazing,” said Red Sox first baseman Mike Napoli, who led the majors in pitches per plate appearance this season (4.59) “He has had some key at-bats in these playoffs where he was down 0-2 and able to draw a walk, which is really impressive with the caliber of pitching we’ve been facing. Yeah, he’s been real impressive.”

Plate discipline has been a work in progress for the Sox uber-prospect. He pointed out he drew just one walk in 97 plate appearances for the Double A Portland Sea Dogs last season.

“It’s just that as a young player you want to hit, you want to hit so bad, you just want to swing at whatever,” said Bogaerts. “As you get experience and you get to the higher levels you got to know that the pitchers are getting better, so you have to get better also.”

Despite those calling for the bat of Stephen Drew, who has an anemic slash line of .086/.111/.143 in the postseason, his glove is simply too valuable at shortstop. That should be obvious after watching the Tigers beer-league softball defense hand the Sox extra outs.

Bogaerts is the shortstop of the future for the Red Sox, the door stopper for a position that has been a revolving door since Nomar Garciaparra, and the answer to what would have happened if the Sox had held on to Hanley Ramirez.

He admits it is the position where his heart lies and his instincts thrive.

“At third . . . for me to play I’ll do it, especially in the World Series, the playoffs,” said Bogaerts. “If they want me to shag fly balls in the outfield to play in the World Series I’ll do it. Who wouldn’t, you know? It’s not easy. I put in a lot of work to try to make it happen. It’s paying off so far, but there is always something about shortstop that has me. I feel different at shortstop than third base.”

Bogaerts has such poise and perspective that the only signs he’s a postseason neophyte are his futile facial hair and the sobering “1992” birthdate next to his name in the media guide.

Don’t worry about a thing, Bogaerts is going to be more than all right in the World Series.